Development of high brightness and high average power picosecond thin disc laser

for short wavelength light sources in HiLASE project (S24)

Taisuke Miura, Michal Chyla, Martin Smrž, Siva Sankar Nagisetty, Patricie Severová,

Ondřej Novák, Pawel Sikocinski, Akira Endo, and Tomáš Mocek

This work benefited from the support of the Czech Republic’s Ministry of Education, Youth and Sports to the HiLASE (CZ.1.05/2.1.00/01.0027) and DPSSLasers (CZ.1.07/2.3.00/20.0143) projects cofinanced from the European Regional Development Fund.

•HiLASE: High average power pulsed LASErs

•European project on strategic development of advanced solid-state laser technologies based on diode pumping (thin-disk laser, multi-slab laser)

•Potential for novel industrial applications using pulsed, high-energy & high-average power DPSSL

The HiLASE Project

Implementation Phase

Demonstration / Technology Transfer

Operation Phase

2011 2012 2013 2014 2015 2016 2017 2011/9 2015/9

Present Status of HiLASE Facility

Web camera

http://hilase.cz/en

Thin Disk-Based High Power Picosecond Laser Beamlines in the HiLASE Project

Beamline-C Beamline-B

0.5 J, 1-2 ps, 1 kHz 5 mJ, 1-2ps, 100 kHz

Beamline-A

0.75 J, <3 ps, 1.73 kHz

Sub-contract

1.3 kW

Main

1 J, 1-2 ps, 120 Hz

100 mJ, 1-2 ps, 1 kHz

Pulse compressor

Pulse compressor

Cryogenic

Slab amplifier

Booster 100 W

120 W 500 W 500 W

Pulse compressor

Regenerative

Amplifier

Pulse stretcher

Oscillator

Pulse compressor

Oscillator

Pulse stretcher

Regenerative

Amplifier

Ring amplifier

Pre

Main

Until Sep. 2015

A B

C

A B

C

Industrial and Medical Applications Using High Energy Picosecond Pulse Based on Thin Disk Technology

EUV/BEUV metrology

Pre-pulse laser for EUV/BEUV

lithography

Laser micromachining

MID-IR pulse source for Bio-medical applications

MID-IR pulse source for LIDT

Soft X-ray source via laser induced plasma or HHG

X-ray source via laser Compton

Water window applications

EUV micro-machining

During the Building Construction

Present Status of Beamlines Development

45-mJ, 1-kHz

25-W, 100-kHz 50-W, 10-kHz

30-mJ, 1-kHz

50-W, 100-kHz

30 Jul. 2012 30 Oct. 2012

High Repetition Rate Regenerative Amplifier

50-W, 100-kHz, 1.3-nm

Yb doped fiber oscillator (1030nm, 50MHz, 20nm,

40nJ, 5ps)

CW 969&940nm

pump

Beam Line

C

Quantum defects 8.7 % @ 940 nm 5.9 % @ 969 nm

18 nm (FWHM@940 nm)

2.8 nm (FWHM@969 nm)

Wavelength stabilized laser diode by using Volume Bragg Grating (VBG)

Pumping at Zero-Phonon-Line of Yb:YAG

96

9 n

m

Zero

-ph

on

on

-lin

e

Characteristics of CW Output CW output without Pockels cell

90W 132W

107W 55W

35W 45W

940-nm pump 969-nm pump

52W, 100kHz-Regenerative Amplifier

0.5mJ, 100kHz, 1.1 ps

• 2.3nm bandwidth • 32% slope efficiency • 15% optical-optical eficiency • 2.8mm pumpspot (diameter) • 91 roundtrips • 100kHz/0.5mJ after compression • 2.55m cavity length

100 150 200 250 300 350 4000

15

30

45

60

100kHz, 969nm

Outp

ut po

we

r [W

]

Pump power [W]

0

5

10

15

Optical Table

Thin disk

Wavefront sensor

Probe source

(852-nm)

Shortwave pass filer

Experimental Setup of In-situ Thin Disk Deformation Measurement

Precise Measurement of Thin Disk Deformation

Cooling water: Off Cooling water: On

Disk

Cooling water

Displacement less than 40-nm can be detected.

Rela

tive w

avefr

ont

change

Rela

tive w

avefr

ont

change

Cylindrical Deformation of Yb:YAG Thin Disk Under The Lasing Operation

4000

4500

5000

5500

6000

6500

0 50 100 150 200 250 300

0.0 0.8 1.6 2.4 3.2 4.1 4.9

RO

C o

f th

in d

isk

[m

m]

Pump power [W]

Pump Intensity [kW/cm2]

Lasing: HorizontalVertical

Non-lasing: HorizontalVertical lasing

Lasing

Non-lasing

Present Status of Beamlines Development

45-mJ, 1-kHz

25-W, 100-kHz 50-W, 10-kHz

30-mJ, 1-kHz

50-W, 100-kHz

30 Jul. 2012 30 Oct. 2012

High Energy Regenerative Amplifier With pulsed zero-phonon-line pumping

Beam Line

B 45 mJ @ 1 kHz

Yb doped fiber oscillator 1030 nm, FWHM 20-30 nm,

50 MHz, 40 nJ, 3-7 ps

Faraday rotator

BBO Pockels cell

Thin

dis

k la

ser

hea

d

LD 969 nm, 1000 W, VBG,

CW&QCW

Optical isolator

λ/4 λ/2

PBS

PBS TFP

lens lens

HR

HR

HR

HR

HR HR

CAV

CAV

VEX

HR

HR

HR

HR

HR

HR

HR

lens

HR

30 mJ, eff. 12.2 % Pump Pulse

Length 900 µs

Pump Pulse

Length 700 µs

Pump Pulse

Length 500 µs

30 mJ, eff. 15.7 % 24 mJ, eff. 19 %

Pulsed Pumping in 1-kHz Regenerative Amplifier

0.3-0.9 ms

1-ms

~2

60

-W

t Pump pulse shape

45-mJ Output with 1-kHz, 0.5-ms Pulsed Pumping at 969-nm

~20% O-O efficiency

M2 measurement of HERA

M2

Horizontal Vertical

1.25 1.23

Far-field profile

Spot diameter: 50 mm

Beam pointing stability

Measurement time: 15 min

-3.5

-2.5

-1.5

-0.5

0.5

1.5

2.5

3.5

-3.5 -2.5 -1.5 -0.5 0.5 1.5 2.5 3.5

Ve

rtic

al D

isp

lace

me

nt

[mm

]

Horizontal Displacement [mm]

RMS pointing stability: -horizontal: 3.8-µrad - vertical: 3.3-µrad

• Overview of the HiLASE Project

• Present status of thin disk laser development

– Beamline-B: 45-mJ, 1-kHz (Pulsed pumping)

– Beamline-C: 52-W, 100-kHz

• Beam quality: M2=1.25X/1.23Y

• RMS pointing stability: 3.8-µradX/3.3-µradY

Summary

http://hilase.cz/en